I got a cheap one. It does have a bit that over hangs as it fits when the seats are folded down. It's not a tidy fit. It's slung in and hooks around the head rests. Does the job. Within the first week of it being in a carton of milk burst in the back and it saved the carpet from being completely ruined! I shoved it in the washer and put it back in and it's been free from accident since then
Thanks I'm not sure as i do have a liner i can use when the seats are folded back but OTOH i could just it that for trips to the dump or garden centre and keep it folded up otherwise, and it does protect the back of the back seats as well.
EDIT: The purchasing dept approves and has authorised me to buy. I take it the dog isnt obligatory? In lieu of a car alarm?